Calculation Examples Of Overall Accuracy - M-system M3LU2 Operating Manual

12.1.8 CALCULATION EXAMPLEs OF OVERALL ACCURACY

■ DC INPUT
(1) 0 to 200 mV DC
Absolute value accuracy [Table 1]: 40 μV
40 μV ÷ 200000 μV × 100 = 0.02% < 0.1%
➠ Overall accuracy = ±0.1% of span
(2) 0 to 4 mV DC
Absolute value accuracy [Table 1]: 10 μV
10 μV ÷ 4000 μV × 100 = 0.25% > 0.1%
➠ Overall accuracy = ±0.25% of span
■ THERMOCOUPLE INPUT
(1) K thermocouple, -150 to +1370°C
Absolute value accuracy [Table 2]: 0.25°C
CJC error (1.0°C) added: 1.25°C
1.25°C ÷ (1370°C – -150°C) × 100 = 0.082% < 0.1%
➠ Overall accuracy including CJC error = ±0.1% of span
(2) K thermocouple, 50 to 150°C
Absolute value accuracy [Table 2]: 0.25°C
CJC error (1.0°C) added: 1.25°C
1.25°C ÷ (150°C – 50°C) × 100 = 1.25% > 0.1%
➠ Overall accuracy including CJC error = ±1.25% of span
■ RTD INPUT
(1) Pt 100, -200 to 800°C
bsolute value accuracy [Table 3]: 0.15°C
0.15°C ÷ (800°C – -200°C) × 100 = 0.015% < 0.1%
➠ Overall accuracy = ±0.1% of span
(2) Pt 100, 0 to 100°C
Absolute value accuracy [Table 3]: 0.15°C
0.15°C ÷ 100°C × 100 = 0.15% > 0.1%
➠ Overall accuracy = ±0.15% of span
■ REsIsTANCE INPUT
(1) 0 to 1000 Ω
Absolute value accuracy [Table 4]: 0.1 Ω
0.1 Ω ÷ 1000 Ω × 100 = 0.01% < 0.1%
➠ Overall accuracy = ±0.1% of span
(2) 0 to 50 Ω
Absolute value accuracy [Table 4]: 0.1 Ω
0.1 Ω ÷ 50 Ω × 100 = 0.2% > 0.1%
➠ Overall accuracy = ±0.2% of span
■ POTENTIOMETER INPUT
(1) 300 to 800 Ω (total resistance 1000 Ω)
Absolute value accuracy [Table 5]: 0.1 Ω
0.1 Ω ÷ (800 Ω – 300 Ω) × 100 = 0.02% < 0.1%
➠ Overall accuracy = ±0.1% of span
(2) 30 to 80 Ω (total resistance 100 Ω)
Absolute value accuracy [Table 5]: 0.1 Ω
0.1 Ω ÷ (80 Ω – 30 Ω) × 100 = 0.2% > 0.1%
➠ Overall accuracy = ±0.2% of span
M3LU2 OPERATING MANUAL EM-2653-B Rev.0 44